Mechanical sound record in film



April 4, 1939. J. H. ROUSE MECHANICAL SO UND RECORD IN FILM Filed Sept. 6-, 1935 INVENTOR lilli Patented Apr. 4, 1939 UNITED STATES 2,158,529 MECHA CAL SOUND RECORD EN ii liiilti John H. Rouse, L

S. A. Sollie,

2 Claims.

This invention relates to a mechanical record of sound and means for producing it. ticular, the invention comprehends a mechanical record 01 sound produced in ordinary motion picture film or the like.

An important object of the invention is to pro vide a mechanical sound record in motion picture film, or the like, which will be durable in use for reproduction of the sound, and which is not the thickness of the film.

A further object of the invention is to provide a mechanical sound record that may be produced in film that has the positive picture already developed thereon.

Other objects and advantages of the invention will be apparent during the course of the follow ing description.

Sound has been recorded mechanically on motion picture film by cutting a phonic line or groove near the edge of the film. As ordinary film is only about .006 inch thick, even with a shallow groove, the film is out about half-way through and so there is a likelihood of the film cracking at the groove with handling. Also, the thinness of the film does not permit cutting a groove deep enough to give reasonable safety the needle jumping the groove in the reproduction of the sound.

In the present invention a phonic line or groove without substantially removing any of the film. The groove is film by the recording stylus so that the material displaced protrudes on the opposite side of the film from the groove.

Referring to the drawing:

Figure l is a view in plan showing a fragmentary length of motion picture film to which the sound record has been added;

fragmentary cross 2'2, showing the is an enlarged, section of Fig. 1 along line area around groove l2;

Figure 3 is a fragmentary side elevation of the recording and/ or reproducing system;

Figure 4 is an enlarged, fragmentary cross section of Fig. 3 along line Figure 5 is a similar view to Fig. a modified form of roller.

At I2 in Fig. 1 is shown. the phonic line which may be located at any convenient distance from the edge of the film or the sprocket holes and may be omitted in the projection of the picture by a mask in the projector. The magnified cross section view of the area around the phonic groove in Fig. 2 shows the swaged or creased groove Figure 2 4, but shows with the material displaced at H. At ll is shown Angeles, L05 Angeles, Calif.

Application September '6, 1935, Serial No.

Calif.. aasignor to a sprocket or roller for supporting and driving the film at constant speed while it is being recorded or reproduced. i5 is a stylus or needle actuated by the sound frequencies through the electro-magnetic, or similar, head it. 5 The magnified cross section view of Fig. 4 shows the formation of the sound record. stylus l5 has a smooth, conical-shaped end with slightly rounded point which bears against the film and presses it into the groove H in the roller. m The stylus may preferably be a jewel. The pres sure on the stylus may be regulated by weighting the stylus-holding head or the arm carrying it, or by similar means. The bottom of the groove l1 forms a stop, limiting the depth of the groove formed in the film by the stylus. The groove is made wide enough to permit lateral movement of the stylus in the directions of the arrows on sa This side movement produces the sound modulation of the groove in accordance with the sound-frequency-actuated motion 01 produced by the driving head while recording sound.

At IS in Fig. 5 is shown a recess filled with a resilient material such as rubber. is has a similar function to the groove ii and is an alternative means for permitting the creasing or swaging oi the him by the recording stylus.

Reproduction of sound from such a record is by a similar method to the recording except that the stylus is then actuated by the modulation of the phonic line instead of producing it. The recording and reproducing methods that they will not be further is common in other terms 0! him recording, the sound is displaced a definite number of frames from the picture.

The advantages of this invention may be realized by consideration of the film in which the record is made. The film is relatively. soft and so a large surface contact of the reproducing stylus is necessary to prevent excessive wear. This requires a relatively large, deep groove. On the film, this is not possible with a cut groove. But, by this invention, no appreciable material is lost in the formagrcove and the material surrounding the walls of the groove is toughened by the deformation of it. The groove can also be made deep enough so that there is less danger of the stylus jumping the groove in reproduction, even with greater amplitude of modulation than is usual. This invention is particularly valuable when it is desired to add sound to film that already bears the positive picture. 5

In the foregoing description, lateral modu1a the phonic groove has been considered, but it will be and dale modulation of the groove may be produced by moving the stylus vertical recording.

While I have described the principle of operation of my invention together wit the appended claims.

I claim: 1. In a system for forming a sound record in motion picture film, a roller to support and drive said film, said roller having an annular recess at least on millimeter deep filled with a resilient material with sound frequencies.

2. Apparatus for film in the form of a phonic groove depressed in and a support for 15 JOHN H. ROUSE. 

